Stone Formation Linked to Hemoglobin A1c Levels

Finding could explain the association between obesity and diabetes and the development of kidney stones.

The following article is part of conference coverage from the 2017 American Urological Association meeting in Boston. Renal and Urology News' staff will be reporting live on medical studies conducted by urologists and other specialists who are tops in their field in kidney stones, prostate cancer, kidney cancer, bladder cancer, enlarged prostate, and more. Check back for the latest news from AUA 2017.

BOSTON—Study findings presented at the American Urological Association 2017 annual meeting may explain the known associations between both obesity and diabetes and the formation of kidney stones.

Greater body mass index (BMI) and type 2 diabetes mellitus are associated with an increased risk of kidney stones, and increased urinary excretion of oxalate has been associated with increasing BMI. In a retrospective study of 24-hour urine collections from 665 unique non-cystinuric adult stone formers, Kyle D. Wood, MD, and colleagues at the University of Alabama at Birmingham examined whether there are associations between BMI and urinary oxalate excretin as well as hemoglobin A1c (A1c) levels and urinary oxalate output. The cohort had an average BMI of 29.2 kg/m2. Of the 665 patients, 1.4% were underweight, 26.5% were normal weight, 35.8% were overweight, 27.7% were obese, and 8.6% were morbidly obese.

Results showed that there were significant positive correlations between A1c and oxalate excretion. BMI was also positively correlated with oxalate excretion and this finding held true for both female and male patients, as well as Caucasians and African Americans.

“We believe that these findings are related to differences in endogenous oxalate synthesis,” Dr Wood told Renal & Urology News. “Carefully controlled dietary studies are needed to elucidate the mechanisms involved. Modulating the endogenous oxalate pathways may be beneficial and warrants further investigation in the obese and diabetic cohorts.”